The present invention relates to multimedia applications and, in particular, to displaying video applications at an increased video framerate.
While the transmission bandwidth rate across computer networks continues to grow, the amount of data being transmitted is growing even faster. Computer users desire to transmit and receive more data in an equivalent or lesser time frame. The current bandwidth constraints limits this ability to receive more data in less time as data and time, generally, are inversely related in a computer networking environment. One particular type of data being transmitted across the various computer networks is a video signal represented by a series of frames. The limits on bandwidth also limit the frame rate of a video signal across a network which in turn lowers the temporal picture quality of the video signal being produced at the receiving end.
Applying real-time frame interpolation to a video signal increases the playback frame rate of the signal which in turn provides a better quality picture. Without requiring an increase in the network bandwidth, frame interpolation provides this increase in the frame rate of a video signal by inserting new frames between the frames received across the network. Applying current real-time frame interpolation techniques on a compressed video signal, however, introduces significant interpolation artifacts into the video sequence. Therefore, for these and other reasons there is a need for the present invention.
In one embodiment, a method includes selecting a number of blocks of a frame pair and synthesizing an interpolated frame based on those selected blocks of the frame pair. Additionally, the synthesis of the interpolated frame is aborted upon determining the interpolated frame has an unacceptable quality.
In another embodiment, a method includes selecting a block size based on a level of activity for a current frame and a previous frame and synthesizing an interpolated frame based on the selected block size of these two frames.
In another embodiment, a method includes maintaining a number of lists, wherein each list contains a current winning block, for a number of interpolated blocks of an interpolated frame for determining a best-matched block from a frame pair for each interpolated block. Additionally, the best-matched block for each interpolated block is selected from the current winning block for each list based on an error criterion and an overlap criterion. The interpolated frame is synthesized based on the best-matched block for each interpolated block.
In another embodiment, a method includes selecting a zero motion vector for a given pixel in an interpolated frame upon determining a current pixel in a current frame corresponding to the given pixel in the interpolated frame is classified as covered or uncovered. The interpolated frame is synthesized based on selecting the zero motion vector for the given pixel in the interpolated frame upon determining the current pixel in the current frame corresponding to the given pixel in the interpolated frame is classified as covered or uncovered.
In another embodiment, a method comprises classifying a number of pixels in a current frame into one of a number of different pixel classifications for synthesis of an interpolated frame. The synthesis of the interpolated frame is aborted and a previous frame is repeated upon determining the interpolated frame has an unacceptable quality based on the classifying of the number of pixels in the current frame.
In another embodiment, a method includes selecting a best motion vector for each of a number of blocks for a hypothetical interpolated frame situated temporally in between a current frame and a previous frame. The best motion vector is scaled for each of the number of blocks for the hypothetical interpolated frame for a number of interpolated frames a relative distance of the number of interpolated frames from the current frame. The number of interpolated frames are synthesized based on the best motion vector for each block within the number of interpolated frames.